Instruction Manual

Instruction Manual
D103605X012
Maintenance and Troubleshooting
January 2015
66
5. Adjust the resistance of the 1 kilohm potentiometer until the voltage read on the voltmeter is 10.0 volts.
6. Record the current shown on the milliammeter.
7. If the current recorded in step 6 is the same as that recorded in step 4 (± 0.08 mA), the voltage available is
adequate.
8. If the voltage available is inadequate, refer to Wiring Practices in the Installation section.
Restart Processor
This is a “soft” reset of the device. This procedure can only be performed while the instrument is out of service. A soft
reset will immediately put into effect changes that have been sent to the instrument. Also, if the device is configured
to shutdown on an alert, the soft reset will clear the shutdown.
Table 6‐3. Instrument Troubleshooting
Symptom Possible Cause Action
1. Analog input reading at
instrument does not match
actual current provided.
1a. Control mode not Analog. 1a. Check the control mode using the Field Communicator. If in
the Digital or Test mode, the instrument receives its set point as
a digital signal. Control is not based on input current. Change
Control Mode to Analog.
1b. Low control system compliance voltage. 1b. Check system compliance voltage (see Wiring Practices in
the Installation section.
1c. Instrument shutdown due to self test failure. 1c. Check instrument status using the Field Communicator (see
Viewing Instrument Status in the Viewing Device Information
section).
1d. Analog input sensor not calibrated. 1d. Calibrate the analog input sensor (see Analog Input
Calibration in the Calibration section).
1e. Current leakage. 1e. Excessive moisture in the terminal box can cause current
leakage. Typically the current will vary randomly if this is the
case. Allow the inside of the terminal box to dry, then retest.
2. Instrument will not
communicate.
2a. Insufficient Voltage Available. 2a. Calculate Voltage Available (see Wiring Practices in the
Installation section). Voltage Available should be greater than or
equal to 10 VDC.
2b. Controller output Impedance too low. 2b. Install a HART filter after reviewing Control System
Compliance Voltage requirements (see Wiring Practices in the
Installation section).
2c. Cable capacitance too high. 2c. Review maximum cable capacitance limits (see Wiring
Practices in the Installation section).
2d. HART filter improperly adjusted. 2d. Check filter adjustment (see the appropriate HART filter
instruction manual).
2e. Improper field wiring. 2e. Check polarity of wiring and integrity of connections. Make
sure cable shield is grounded only at the control system.
2f. Controller output providing less than 4 mA to loop. 2f. Check control system minimum output setting, which should
not be less than 3.8 mA.
2g. Disconnected loop wiring cable at PWB. 2g. Verify connectors are plugged in correctly.
2h. PWB DIP switch not set properly. 2h. Check for incorrect setting or broken DIP switch on the back
of the PWB. Reset switch or replace PWB, if switch is broken. See
table 6‐2 for switch setting information